Enhanced Accuracy Gun Iron Sighting System

ABSTRACT

Rugged, rapid-target-acquisition iron sighting systems in which least one of the front sight and the rear sight has a multiple-lead thread elevation screw post for vertically adjusting a sighting point are disclosed. The use of a multiple-lead thread elevation screw post permits the relatively fast adjustability of a coarse threaded screw post while providing the stability of a fine-threaded screw post. Embodiments of the present invention also include guns equipped such iron sighting systems.

FIELD OF THE INVENTION

The present invention relates to an enhanced accuracy iron sightingsystem that is suitable for use on guns, especially heavy guns such asmachine guns.

BACKGROUND OF THE INVENTION

To persons skilled in the art, the interchangeable terms “iron sights”and “iron sighting systems” refer to target sighting systems for gunsconsisting of aligned markers which rely on the visual acuity of theshooter, unaided by optical magnification devices, to bring the markersand target into alignment. Typically, an iron sighting system willconsist of a front sight located near the projectile-exiting end of thegun and a rear sight located near the shooter. Most guns are equippedwith iron sights, even those that are also equipped with moresophisticated target sighting systems, e.g. telescopic sights, as ironsights can be used in case of the inoperability of the moresophisticated target sighting systems.

The design of iron sights is of ancient origin dating back to thedevelopment of the first guns. Over the years advancements have beenmade. Some of these advancements are described in the following U.S.patents and published patent applications: U.S. Pat. No. 870,272 issuedNov. 5, 1907 to Burton; U.S. Pat. No. 2,336,107, issued Dec. 7, 1943 toLitschert; U.S. Pat. No. 2,336,108, issued Dec. 7, 1943 to Lowe; U.S.Pat. No. 2,864,168, issued Dec. 16, 1958 to Sampson; U.S. Pat. No.3,165,836, issued Jan. 19, 1965 to Magardo; U.S. Pat. No. 3,626,597,issued Dec. 14, 1971 to Darrah; U.S. Pat. No. 4,127,943, issued Dec. 5,1978 to Tiritilli; U.S. Pat. No. 4,264,123, issued Apr. 28, 1981 toMabie; U.S. Pat. No. 4,536,966, issued Aug. 27, 1985 to Engel; U.S. Pat.No. 4,606,131, issued Aug. 19, 1986 to Domian; U.S. Pat. No. 4,686,770,issued Aug. 18, 1987 to Aigner; U.S. Pat. No. 4,691,442, issued Sep. 8,1987 to Center; U.S. Pat. No. 5,533,292, issued Jul. 9, 1996 to Swan;U.S. Pat. No. 5,930,906, issued on Aug. 3, 1999 to Howe et al.; U.S.Pat. No. 5,983,774, issued Nov. 16, 1999 to Mihaita; U.S. Pat. No.6,513,276 B2, issued Feb. 4, 2003 to Mendoza-Orozco; U.S. Pat. No.6,860,056 B2, issued Mar. 1, 2005 to Howe; U.S. Pat. No. 7,181,882 B2,issued Feb. 27, 2007 to Woodbury; U.S. Pat. No. 7,356,962 B2, issuedApr. 15, 2008 to Swan; Publication No. 2009/0038202 A1, published Feb.12, 2009 for Nemec; Publication No. 2009/0049734 A1, published Feb. 26,2009 for Storch et al.; and Publication No. 2009/0188147 A1, publishedJul. 30, 2009 for Schwerman et al.

Despite the crowdedness of the art, there is still room for improvement,especially for iron sights for use on heavy guns, such as machine gunsof calibers of 50 and above. The aforementioned Publication No.2009/0038202 A1, which is a publication of a co-pending patentapplication of the inventor of the present invention, solves some of theproblems of the prior art by providing a rugged iron sighting systemhaving superior position-locking mechanisms and superiorquick-target-acquisition features. Nonetheless, the inventor has madeyet further improvements to iron sighting systems in developing thepresent invention, as described below.

SUMMARY OF THE INVENTION

The present invention provides rugged, quick-target-acquisition (“QTA”)iron sighting systems wherein at least one of the front sight and therear sight has a multiple-lead thread elevation screw post forvertically adjusting a sighting point. The use of a multiple-lead threadelevation screw post permits the relatively fast adjustability of acoarse-threaded screw post while providing the stability of afine-threaded screw post. Embodiments of the present invention alsoinclude guns equipped such iron sights. Embodiments of the presentinvention also include individual front sights and rear sights havingmultiple-lead thread elevation screw posts usable as part of an ironsighting system for a gun.

BRIEF DESCRIPTION OF THE DRAWINGS

The criticality of the features and merits of the present invention willbe better understood by reference to the attached drawings. It is to beunderstood, however, that the drawings are designed for the purpose ofillustration only and not as a definition of the limits of the presentinvention.

FIG. 1 is a perspective view showing a first embodiment of the presentinvention mounted on a M2HB 50 caliber machine gun in an MK 93 cradlemount.

FIGS. 2A and 2B are, respectively, the schematic top and side views ofthe embodiment of the present invention shown in FIG. 1 mounted on aM2HB 50 caliber machine gun.

FIG. 3 is a perspective view of the front and rear sights of theembodiment of the present invention shown in FIG. 1 oriented toillustrate their respective shooter-facing sides.

FIG. 4A is an elevational view, partly in cross-section, of theshooter-facing side of the rear sight shown in FIG. 3.

FIG. 4B is an elevational view, partly in cross-section, of the apertureslide shown in FIG. 4A.

FIG. 4C is side elevational view, partly in cross-section, of theaperture slide of FIG. 4B.

FIG. 4D is an elevational view, partly in cross-section, of the springdetent plunger assembly of the rear sight shown in FIG. 4A.

FIG. 5A is an elevational view of the target-facing side of the rearsight shown in FIG. 3.

FIG. 5B is an elevational view, partly in cross-section, of either ofthe upward facing detent plungers of the rear sight shown in FIG. 5A.

FIG. 5C is an elevational view, partly in cross-section, of the detentplunger carried by the windage knob of the rear sight shown in FIG. 5A.

FIGS. 6A and 6B are side elevational views, partly in cross-section,showing the shooter's left side of the rear sight shown in FIG. 3 in thestorage and operational positions, respectively.

FIG. 6C is side elevational view, partly in cross-section, showing aportion of the first vertical arm of the rear sight shown in FIG. 6Billustrating an elevation scale marked in mils.

FIG. 7 is top view, partly in cross-section, of the rear sight shown inFIG. 6A in the storage position.

FIG. 8A is an elevational view, partly in cross-section, of theshooter-facing side of a rear sight in accordance with a secondembodiment of the present invention.

FIG. 8B is an elevational view, partly cross-section, of a portion ofthe rear sight shown in FIG. 8A illustrating a portion of the flat headplunger stop assembly.

FIGS. 9A and 9B are side elevational views showing the shooter's leftside of the rear sight shown in FIG. 8A in the storage and operationalpositions, respectively.

FIGS. 9C and 9D are, respectively, top and side views, partly incross-section, of the flat head plunger position stop of the rear sightshown in FIG. 9B.

FIG. 10 is an elevational view, partly in cross-section, of thetarget-facing side, of the rear sight shown in FIG. 8A.

FIG. 11A is an elevational view, partly in cross-section, of theshooter-facing side of a rear sight in accordance with a thirdembodiment of the present invention.

FIG. 11B is an elevational view, partly cross-section, of a portion ofthe rear sight shown in FIG. 11A illustrating a portion of the V-slotplunger stop.

FIGS. 12A and 12B are side elevational views, partly in cross-section,showing the shooter's left side of the rear sight shown in FIG. 11A inthe storage and operational positions, respectively.

FIG. 12C is a side elevation view, partly in cross-section, alongcutting plane 12C-12C in FIGS. 11B and 12B showing the interaction ofthe V-slot head plunger and the groove in the aperture housing of therear sight shown in FIG. 12B.

FIGS. 12D and 12E are, respectively, top and side views, partly incross-section, of the V-slot head plunger position stop of the rearsight shown in FIG. 11B.

FIG. 13 is an elevational view, partly in cross-section, of thetarget-facing side of the rear sight shown in FIG. 11A.

FIG. 14 is an elevational view, partly in cross-section, of theshooter-facing side of a rear sight in accordance with a fourthembodiment of the present invention.

FIGS. 15A and 15B are side elevational side views, partly incross-section, showing the shooter's left side of the rear sight shownin FIG. 14A in the storage and operational positions, respectively.

FIG. 15C is a side elevational view of a threaded pin for operablyguiding the elongated V-slot plunger assembly of the rear sight shown inFIG. 15A.

FIG. 15D is a side elevation view, partly in cross-section, alongcutting plane 15D-15D in FIGS. 15B and 16B showing the interaction ofthe elongated V-slot head plunger and the groove in the aperture housingof the rear sight shown in FIG. 15B.

FIGS. 15E and 15F are, respectively, top and side views, partly incross-section, of the elongated V-slot elongated head plunger positionstop of the rear sight shown in FIG. 15B.

FIG. 16A is an elevational view, partly in cross-section, of thetarget-facing side of the rear sight shown in FIG. 14A.

FIG. 16B is an elevational side view, partly in cross-section, of aportion of the rear sight shown in FIG. 16A illustrating a portion ofthe elongated V-slot plunger stop assembly.

FIG. 17 is an elevational view, partly in cross-section, of theshooter-facing side of a rear sight in accordance with a fifthembodiment of the present invention.

FIGS. 18A and 18B are side elevational side views, partly incross-section, showing the shooter's left side of the rear sight shownin FIG. 17 in the storage and operational positions, respectively.

FIG. 19 is a top view, partly in cross-section, of the rear sight shownin FIG. 17 in the storage position.

FIG. 20 is an elevational view, partly in cross-section, of thetarget-facing side of the rear sight shown in FIG. 17.

FIG. 21A is an elevational view, partly in cross-section, of theshooter-facing side of the front sight shown in FIG. 3.

FIG. 21B is a elevational view, partly in cross-section, illustratingthe interaction of the front elevation screw post and roll pin of thefront sight shown in FIG. 21A.

FIG. 21C is an side elevational view, partly in cross-section,illustrating the interaction of the front elevation screw post and rollpin of FIG. 21B.

FIG. 21D is an elevational view, partly in cross-section, of a detentplunger that interacts with the front elevation knob.

FIG. 22 is an elevational view, partly in cross-section, showing theshooter's left side of the front sight shown in FIG. 21A.

FIG. 23 is an elevational view, partly in cross-section, of thetarget-facing side of the front sight shown in FIG. 21A.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In this section, some preferred embodiments of the present invention aredescribed in detail sufficient for one skilled in the art to practicethe present invention. It is to be understood, however, that the factthat a limited number of preferred embodiments are described herein doesnot in any way limit the scope of the present invention as set forth inthe appended claims. Please note that, generally speaking, the samereference numerals are used for the same components regardless of theembodiment of the present invention in which the component appears.Alternate reference numerals are used, however, in some cases where acomponent has different features in one embodiment than in another.

Persons skilled in the art will understand that while the QTA ironsights of the present invention are usable on many types of guns,including sniper rifles, they are most well suited for use on heavy gunssuch as swivel mounted machine guns, regardless of the cradle style usedfor supporting the machine gun. Some examples of such machine guns are50 caliber machine guns of the following types: Browning models M2HB,M3HB flexible, M3, and M3M.

Referring to FIG. 1, there is shown in perspective, from the shooter'sside of the gun, an iron sight according to an embodiment of the presentinvention attached to a M2HB 50 caliber machine gun 2, mounted on a MK93cradle 4. The embodiment includes a front sight 6 and a rear sight 8. Aswill be described in more detail below, both of these sights 6, 8 areelevation and windage adjustable and releasably lockable.

FIGS. 2A and 2B, show schematic top and side views of the front sight 6and the rear sight 8 of the previously mentioned embodiment of thepresent invention attached to the receiver portion 10 of a 50 calibermachine gun 12. Persons skilled in the art will quickly recognize that,in this preferred embodiment, the sightline 14 extending between thefront and rear sights is significantly higher above the top of thereceiver portion 10 of the machine gun 12 than are the sightlines ofmost prior art iron sights, thus reducing or eliminating the need forthe shooter to crouch down to use the sights to acquire a target. Thisincreased sightline height 16, in combination with the relatively largesight window 18 and large sight aperture 20 of the rear sight 8 and thelarge sight aperture 22 of the front sight 6 (see FIG. 1) enables theshooter to rapidly acquire a target, to follow a moving target, fire,and to go on to and acquire subsequent targets. A benefit of the quicktarget acquisition capability of the iron sights of the presentinvention is a great savings of ammunition over many prior art ironsights since the invention often makes it possible to effectively use amachine gun to which the iron sights are attached in a semi-automaticmode, rather than in an ammunition-wasting fully automatic mode.

FIG. 3 provides a perspective view of the previously mentioned front andrear sights 6, 8, showing the sides which face the shooter. The externalcomponents of these sights 6, 8 are preferably made of hard and durablematerials, such as 4140 steel and treated with magnesium phosphate,i.e., parkerized, for corrosion resistance. The internal components ofthese sights 6, 8 are preferably made of 1144 stress proof high carbonsteel. Persons skilled in the art will recognize that other materials ofconstruction may be used, but preferably the materials of constructionare chosen with the intent of providing the front and rear sights withthe strength, stiffness, toughness, durability, and corrosion resistancesufficient to provide good service in the anticipated environmentalconditions to which the sights 6, 8 will be subjected during theiroperational lifetimes.

The components of the rear sight 8 shown in FIG. 3 will now be describedwith reference generally to FIGS. 4A through 7. Refer now to FIGS. 4Aand 5A, which show, respectively shooter-facing and target-facing sidesof the rear sight 8. Rear sight 8 has a rear base plate 24 which isadapted to be attached, directly or indirectly, to the receiver portionof a gun. For this purpose, rear base plate 24 has downwardly facingretaining studs 26 designed to be received within positioning holes inthe top surface of the gun receiver and screw holes 28 through whichscrews can be fastened into threaded holes in the gun receiver, but itcould be easily reconfigured by a person skilled in the art to attach toany desired gun.

Rear base cradle 30 is attached to the base plate 24 with screws 32. Therear base cradle 30, by way of rear windage assembly 34, adjustably andlockably carries aperture housing 36 to provide windage (lateral)adjustability and the ability for the rear sight 8 to be folded downinto a storage position and up into an operating position, asillustrated in the views of the rear sight 8 shown from the shooter'sleft presented in FIGS. 6A and 6B, respectively. FIG. 7 shows a top viewof the rear sight 8 in the folded down position of FIG. 6A.

Referring again to FIGS. 4A and 5A, the rear windage assembly 34comprises rear windage screw 38, first and second rear retainingbushings 40, 42 and rear windage knob assembly 44. First and second rearretaining bushings 40, 42 are fixed in place in the opposing verticalarms 46, 48 of the rear base cradle 30 by set screws 50. The rearwindage screw 38 passes through a threaded through-hole in the rearaperture housing and rides on the first and second retaining bushings40, 42. The rear windage knob 51 is fixed to one end of the rear windagescrew 38, e.g., by a retaining pin or screw 54, to permit the shooter toturn the rear windage knob 51 in one direction or the other to cause therear aperture housing 36 to move laterally left or right from theshooter's perspective. The rear windage knob 51 is preferably knurledand carries a spring-loaded detent plunger 52. The detent plunger 52 isbest seen in FIG. 5C, and comprises a spring 53 mounted on the stem-end55 of the detent plunger head 57 At least one of first and second rearretaining bushings 40, 42 has a plurality of depressions, grooves, orholes in its outer face for receiving the detent plunger head 57 toreleasably lock the rear windage knob 51, and consequently, rear windagescrew 38, from inadvertently moving from a selected position.

Preferably, the rear windage assembly 34 is constructed to permit therear windage knob 51 to be interchangeably and selectively located onthe shooter's right or left. For example, the first and second retainingbushings 40, 42 may be made identical to one another so that the windagescrew 38 may be selectively positioned with the rear windage knob 51 onthe shooter's right or left. Another option is to configure each of thefirst and second bushings 40, 42 to be received on either of thevertical arms 46, 48 of the rear base cradle 30, regardless of whetheror not they are otherwise different in other respects.

The rear aperture housing 36 preferably carries one or more springdetent plunger assemblies, e.g., spring detent plunger assembly 56 (bestseen in FIG. 4D), within transverse throughholes for interacting withdetent receiver flat surface, depressions, grooves, or holes, e.g.,detent receiver holes 58, 60, located in vertical arms 46, 48 toreleasably lock the rear aperture housing 36 in either the storage oroperating position. The spring detent plunger assembly 56 includes firstand second detent plunger heads 62, 64 which are urged apart by one ormore springs, e.g. first and second springs 66, 68. Preferably, it alsoincludes a guide rod 70 having reduced diameter end portions forcarrying springs 66, 68 which are invaginated within and axially andoutwardly urge first and second detent plunger heads 62, 64. Otherdetent mechanisms may be used instead of or in addition to one or moresuch spring assemblies for interacting with the detent receiving flatsurface, depressions, grooves, or holes, e.g., detent receiving holes58, 60, located on one or both of the vertical arms 46, 48 of the rearbase cradle 30 for releasably locking the rear sight 8 into either astorage or operating position. For example, spring loaded detentsplungers in blind holes in the rear aperture housing can be used tointeract with receiving holes in the rear base cradle or vice versa.

Referring again to FIGS. 4A and 5A, the rear aperture housing 36 alsocarries the rear elevation assembly 72. The rear elevation assembly 72includes a multiple-lead thread rear elevation screw post 74 whichpermits the relatively faster adjustability of a more coarsely-threadedsingle lead screw post while providing the greater stability of afiner-threaded single lead screw post. The elevation screw post 74passes through a through-hole 76 in the rear aperture housing 36 andoperationally connects the rear elevation assembly 72 to the rearaperture housing 36 by way of rear elevation knob 78, as described inmore detail below. The rear elevation post may have a double, triple,quadruple or even higher number lead thread, but a double lead thread ispreferred since as the lead number increases the precision of verticaladvancement control decreases and the machining costs increase.Nonetheless, in some embodiments of the present invention in which thefront sight utilizes a multiple-lead thread screw post, the rearelevation screw post may have a single-lead thread so as to provide agreater precision in elevation adjustment to the rear sight.

Although the rear elevation screw post 74 may have any type of threadform, one having a sharp crest is preferred due to its lower machiningcosts.

The rear elevation assembly 72 includes a rear elevation knob 78, whichis threaded onto the rear elevation screw post 74 and retained withinthe elevation knob window 80 of the rear aperture housing 36 by theupper and lower surfaces of the elevation knob window 80. Turning therear elevation knob 78 in one direction or the other has the effect ofraising or lowering the top end of the rear elevation screw post 74.Preferably, the outer circumference of the rear elevation knob 78 has aheavily knurled surface. Also, preferably, the bottom face of the rearelevation knob 78 has flat surface, depressions, holes, elongatedvee-slots or other types of grooves for receiving at least oneupward-facing detent plunger, e.g. spring loaded detent plungers 82, 84,mounted within the rear aperture housing 36 for the purpose ofreleasably locking the rear elevation knob 78, and, consequently, rearelevation screw post 74, from inadvertently moving from a selectedposition. The detent plungers 82, 84 can be of any design and arepreferably disposed within threaded cavities so that the spring tensionof the detent plungers 82, 84 applied to the bottom surface of the rearelevation knob 78 can be selectively adjusted by screwing the retainingmechanism for the detent plungers 82, 84 further into or out of thecavities. An example of such detent plunger is shown in FIG. 5B. Thedetent plunger 82 shown there includes a plunger head 83, a spring 85,and a retaining screw 87. The spring 85 is received into a cavity withinplunger head 83 and the retaining screw 87 presses upon the spring 85when the retaining screw 87 is screwed into a cavity in the rearaperture housing 36.

Although it is within the contemplation of the present invention toconfigure the top end 86 of the rear elevation screw post 74 to have therear sighting point of the target sightline, e.g., with a flat surface,a point, a ball, a rounded tip, a vee-notch, or a sight-window, it ispreferred that the rear elevation screw post 74 be operably connected toa component having the sighting point. Such a component is referred toherein as a “sight tip.” It is to be understood that the term “sightingpoint” as used herein is to be construed as meaning the location on orwithin a component of a front or rear sight of an iron sighting systemwhich is used in conjunction with a location on a complementarycomponent of the other of the front or rear sight to define the targetsightline. An example of a sighting point being located on a componentoccurs when the sighting point is located at the apex of a rounded tip.An example of a sighting point being located within a component occurswhen the sighting point is located at the center of a sight window.

Aperture slide 88 is an example of such a sight tip. Preferably, theaperture slide 88 is threadedly attached to the top end 86 of the rearelevation screw post 74, although other types of connections known tothose skilled in the art can be used, e.g., a connection secured by aretaining pin. Aperture slide 88, which is best seen in FIG. 4B,preferably is configured to have a sight window 90 and first and secondslide arms 92, 94. The distal ends of the first and second slide arms92, 94 are received within longitudinal slots within the first andsecond vertical arms 96, 98 of the rear aperture housing 36 to preventthe rotation of the aperture slide 88 and the rear elevation screw post74 to which it is operably attached, to stabilize the position of thesight window 90, and to further ruggedize the rear sight 8 by shelteringaperture slide 88. However, it is also within the contemplation of thepresent invention to additionally or alternatively use other means knownin the art may to prevent the rotation of the rear elevation screw post.One such means is described below for the front elevation screw post inwhich a slot in the screw post is used in conjunction with a fixed pinto prevent elevation screw post rotation.

Preferably, one or more indicator lines, e.g., indicator lines 100, 102,are provided on one or both of the first and second slide arms 92, 94for cooperating with one or more elevation scales provided on one orboth of the first and second vertical arms 96, 98, e.g. first and secondscales 104, 106, to correlate the vertical position of the sight window90 to a target distance. Referring to FIG. 4A, such a scale may begraduated in any desired unit, e.g., feet, yards, meters, kilometers,mils, but preferably is graduated in either meters or yards and thegraduation is split between the first and second vertical arms 96, 98 soas to provide greater resolution to the scale. For example, in apreferred embodiment shown in FIG. 4A, first and second scales 104, 106make up a single scale in meters with the odd numbered distance valuesappearing on the first vertical arm 96 on the shooter's left and theeven numbered distance values appearing on the second vertical arm 98 onthe shooter's right. Preferably, at least one end face 101, 103 of firstand second slide arms 92, 94, respectively, has an indicator 105, whichis visible through a window, e.g., window 99 (see FIG. 6C), forcooperating with a scale 107 which optionally may be provided on anoutward-facing side of one of the first and second arms 96, 98, e.g.,for indicating the elevation setting of the rear sight 8 in mils.

The sight window 90 may be of any desired size or shape, and mayoptionally be provided with cross-hairs or other sighting point locatingaids (not shown). Referring to FIG. 4C, the thickness dimension 109 ofthe sight window, i.e., the dimension parallel to the sight line, can beany desired thickness, e.g. from one-quarter to three-eighths inches.Longer dimensions give the sight window a tunnel appearance and allowfor the use of tapers, e.g., taper 111, at the ends of the tunnel.Preferably, the sight window 90 is a peep sight with a round shape asviewed by the shooter with minimum diameter of between about one-quarterand three-sixteenths inches, a thickness of about three-eighths inchesand has no taper.

A second embodiment of a rear sight 8 a in accordance with the presentinvention will now be described with reference to FIGS. 8A through 10.Refer now to FIGS. 8A and 10 which show, respectively, the rear sight 8a from the shooter-facing and the target-facing sides. The rear sight 8a contains all of the components of rear sight 8 which were describedabove. In addition, rear sight 8 a includes an additional mechanism forreleasably locking the rear sight 8 a into the operating position shownin FIG. 9A. This mechanism is the flat head plunger position stop 170,components of which are best seen in FIGS. 8B, 9C, and 9D. The flat headplunger position stop 170, which is carried by the rear base cradle 30within a cavity 172, cooperates with a receiving flat surface,depression, groove, or hole, e.g. flat surface (see FIG. 8B) located onthe bottom side of rear aperture housing 36. The flat head plungerposition stop 170 comprises a cylindrical plunger 176 having a cavity178 (see FIG. 9D) which receives a spring 180 for urging the plunger 176against its cooperating flat surface, depression, groove or hole whenthe rear aperture housing 36 is rotated from the storage position (seeFIG. 9A) into the upright position (see FIG. 9B). The flat head plungerposition stop 170 is shown in this embodiment as working in conjunctionwith the spring detent plunger assembly 56 for releasably locking therear sight 8 a into the operation position. However, rear sights usingonly a flat head plunger position stop 170 for releasably locking therear sight into the operation position are also within the contemplationof the present invention.

Optionally, the flat head plunger position stop 170 can be used forreleasably locking the rear sight 8 a into the storage position (seeFIG. 9A). This can be done by providing a receiving flat surface,depression, groove, or hole in a suitable location on the target-facingside of the rear aperture housing 36 for receiving the plunger 176 whenthe rear sight 8 a is in the storage position.

A third embodiment of the present invention, rear sight 8 b, will now bedescribed with reference to FIGS. 11A through 13. Like rear sight 8 b,in addition to having all of the components described with regard torear sight 8, rear sight 8 b also includes an additional mechanism forreleasably locking it into its operating position. In this thirdembodiment, the mechanism is a V-slot head plunger position stop 190,the components of which are best seen in FIGS. 11B, 12C, 12D, and 12E.The V-slot head plunger position stop 190 is carried by the rear basecradle 30 within a cavity 192 to cooperate with a receiving flatsurface, depression, groove, or hole located on the bottom side of rearaperture housing 36. The V-slot head plunger position stop 190 comprisesa plunger 196 having a V-shaped head 198 extending from a hollowcylindrical body 200 which receives a spring 202 for urging the V-shapedhead 198 into a groove 204 when the rear aperture housing 36 is rotatedfrom the storage position (see FIG. 12A) into the upright position (seeFIG. 12B). Although the elongated V-slot head plunger position stop 190is shown in this embodiment as working without the spring detent plungerassembly 56 for releasably locking the rear sight 8 b into the operatingposition, it is also within the contemplation of the present inventionto use the elongated V-slot head plunger 190 in conjunction with aspring detent plunger assembly 56.

Optionally, the V-slot plunger position stop 190 can be used forreleasably locking the rear sight 8 b into the storage position (seeFIG. 12A). This can be done by providing a receiving flat surface,depression, groove, or hole, e.g. groove 206 (see FIG. 12C) in asuitable location on the target-facing side of the rear aperture housing36 for receiving the plunger 196 when the rear sight 8 b is in thestorage position.

A fourth embodiment of the present invention, rear sight 8 c, will nowbe described with reference to FIGS. 14 through 16B. This fourthembodiment is similar to the second and third embodiments in that it hasmost of the components described with regard to the first embodiment,the exception being the spring detent plunger assembly 56 and the detentreceiver holes 58, 60 with which it cooperates. Also like the second andthird embodiments, the fourth embodiment includes an additionalmechanism for releasably locking it into the operating position. Likethose mechanisms of those second and third embodiments, the mechanism inthis fourth embodiment comprises a detent plunger which cooperates witha flat surface, depressions, grooves, or holes located on the bottom ofthe rear aperture housing 36 to releasably lock the rear sight 8 c intothe upright position. What is different about the mechanism in rear site8 c is that it uses the combined force of multiple springs to moreforcibly and securably lock it into the desired operating or storageposition. Preferably the size of the detent plunger and its receivingflat surface, depressions, grooves, or holes are also increased so as toprovide increased contact area to further improve the locking effect.

In the rear sight 8 c, the mechanism is an elongated V-slot head plungerposition stop 210, the components of which are best seen in FIGS. 15D,15E, 15F, and 16B. The V-slot head plunger position stop 210 comprises aplunger 212 having an elongated V-shaped head 214 extending from ahollow rectangular body 216 (see FIGS. 15E and 15F), which receivesspring 218, 220, 222 for urging the elongated V-shaped head 214 into agroove 226 when the rear aperture housing 36 is rotated from the storageposition (see FIG. 15A) into the upright position (see FIG. 15B). It isto be understood that it is within the contemplation of the presentinvention that the plunger 212 be used with detent heads having othershapes, including flat or rounded.

The elongated V-slot head plunger position stop 210 is carried by therear base cradle 30 within a cavity 224 to cooperate with a receivingflat surface, depression, groove, or hole, e.g. groove 226 (see FIG.15D) located on the bottom side of rear aperture housing 36 and/or aflat surface, depression, groove, or hole, e.g., groove 228, located onthe target-facing side of the rear aperture housing 36. A pair ofthreaded pins 230, 232, which screw into threaded holes, e.g. threadedhole 234, located on the target-facing side of the rear base cradle 30,are used to operably guide the elongated V-slot head plunger positionstop 210 within the cavity 224. The pin portions, e.g., pin portion 238(see FIG. 15C), of each of the screw-headed pins 230, 232, extendsthrough one of the slots 240, 242 of the body 216 of the plunger 212 tohelp guide the plunger 212 during operation.

A fifth embodiment of the present invention, rear sight 8 d, will now bedescribed with reference to FIGS. 17 through 20. The primary differencebetween the rear sight 8 d and the rear sights 8, 8 a, 8 b, 8 c of theembodiments of the present invention described above is that whereas therear base plate 24 and the rear base cradle 30 are individual componentsin rear sights 8, 8 a, 8 b, 8 c, in rear sight 8 d these two componentsare combined into a single component, i.e. rear cradle 250. Combiningthese two components into one provides the rear sight 8 d with superiorruggedness by eliminating the inter-component connections. In all otherregards, rear sight 8 d may be provided with any of the featuresdescribed above for rear sights 8, 8 a, 8 b, 8 c.

Referring to FIG. 17, in the rear sight 8 d, the rear aperture housing36 is operably connected to rear cradle 250. As best seen in FIGS. 18Aand 18B, the rear cradle 8 d is adapted to be attached, directly orindirectly, to the receiver portion of a gun. For this purpose, the rearcradle 250 has downwardly facing retaining studs 252 designed to bereceived within positioning holes in the top surface of the gun receiverand holes through which screws, e.g., screws 254, can be fastened intothreaded holes in the gun receiver, but it could be easily reconfiguredby a person skilled in the art to attach to any desired gun.

The components of the front sight 6 shown in FIG. 3 will now bedescribed with reference generally to FIGS. 21A through 23. Referringnow to FIGS. 21A through 21D, the front sight 6 has a front base plate108 which is adapted to be attached, directly or indirectly, to thereceiver portion of a gun. For this purpose, front base plate 108 hasdownwardly depending elongated struts 110 which between each other formchannels 112. As shown, each of struts 110 is provided with a pair ofthrough holes, e.g., through holes 114, configured to receive retainingpins, e.g. retaining pin 115, to removably attach the front base plate108 to a prior art machine gun front sight mounting bracket.

The front base plate 108 carries a front base support 116 which, inturn, carries a front aperture housing 118. The front base support 116is configured to be selectively and lockably moved laterally in relationto the front base plate 108 so as to provide windage adjustment for thefront sight 6. Referring now to FIG. 22, preferably, the upper portionof front base plate 108 has a dovetail rail 120 adapted to be receivedin a dovetail groove 122 formed between first and second portions 124,126 of front base support 118. The front base support first and secondportions 124, 126 in conjunction with clamping bolts 128, 130 form aclamp such that loosening or tightening clamping bolts 128, 130 loosensor tightens the sides of the dovetail groove 122 against the sides ofthe dovetail rail 120 of the front base plate 108 to permit the frontbase support 118 to be selectively and lockably moved laterally forwindage adjustment of the front sight 6. This arrangement permits thefront base support 116 to lockably slide along the dovetail rail 120 offront base plate 108 while fixedly carrying the front aperture housing118.

The upper portions of the front base support first and second portions124, 126 also form a slot 132 for clampingly receiving the bottomportion of the front aperture housing 118. Preferably, the dovetailgroove 122 and the slot 132 are dimensioned in relation to one anotherso that tightening the clamping bolts 128, 130 first tightly clamps thefront aperture housing 118 in position between first and second portions124, 126, and further tightening of the clamping bolts 128, 130 isnecessary to clamp the front base support 116 in position on thedovetail rail 120 of the front base plate 108.

Referring again to FIGS. 21A and 23, the front aperture housing 118carries the front elevation assembly 134. The front elevation assembly134 includes a front elevation screw post 136 which preferably has asingle lead thread, but may alternatively have a multiple-lead thread. Asingle lead thread is preferred on the front elevation screw post 136 togive finer elevation adjustment control for the front sight 6.

The front elevation assembly 134 also includes the front elevation knob138 screwed onto the front elevation screw post 136 and retained withinthe front elevation knob window 140 of the front aperture housing 118 bythe upper and lower surfaces of the front elevation knob window 140.Turning the front elevation knob 138 in one direction or the other hasthe effect of elevating or depressing the top end of the front elevationscrew post 136. Preferably, the outer circumference of the frontelevation knob 138 has a heavily knurled surface. Also, preferably, thebottom face of the front elevation knob 138 has flat surface,depressions, holes, elongated V-slots or other types of grooves forreceiving at least one upward-facing detent plunger, e.g. spring loadeddetent plungers 142, 144, mounted within, respectively, front basesupport first and second portions 124, 126 for the purpose of releasablylocking the front elevation knob 138, and consequently, the frontelevation screw post 136, from inadvertently moving from a selectedposition. The detent plungers 142, 144 can be of any design and arepreferably disposed within threaded cavities so that the spring tensionof the detent plungers 142, 144 applied to the bottom surface of thefront elevation knob 138 can be selectively adjusted by screwing theretaining mechanism for the detent plungers 142, 144 further into or outof the cavities. An example of such detent plunger is shown in FIG. 21D.The detent plunger 142 shown there includes a plunger head 143, a spring145, and a hollow retaining screw 147. The plunger head 142 and thespring 145 are received into a cavity within the retaining screw 147.The retaining screw 147 presses upon the spring 145, which in turnpresses upon the plunger head 142, when the retaining screw 147 isscrewed into a cavity in the aperture housing first portion 124.

The top end 146 of the front elevation screw post 136 may be configuredto function as a front sighting point of the target sightline or topermanently or removably receive a sight tip. For example, in someembodiments, the top end 146 of the front elevation screw post 136 andthe front aperture housing are configured to receive an aperture slidein the manner similar to that described above for the rear sight 8.Preferably, however, the top end 146 is configured as sighting post 148.The sighting post 148 preferably has a flat top sighting surface 150,but alternatively may have a point, a ball, a rounded tip, or one ormore grooves or sight windows.

Preferably, the front elevation screw post 136 is provided with alongitudinal slot 151 (see FIG. 21B) for interacting with some device,such as a rod, screw, post, or pin, e.g., roll pin 152 which isremovably affixed to the front aperture housing 118, to prevent thefront elevation screw post 136 from rotating around its longitudinalaxis as it is moved upwardly or downwardly by the rotation of the frontelevation knob 138. The interaction between the roll pin 152 and thefront elevation screw post 136 is illustrated in FIGS. 21B and 21C,which show the roll pin 152 extending through the longitudinal slot 151so as to permit vertical movement of the front elevation screw post 136while at the same time preventing the front elevation screw post 136from rotating about its longitudinal axis. However, other means known inthe art for preventing rotation of the front elevation post 136 are alsowithin the contemplation of the present invention.

As manufactured, the barrel of a gun is typically not fully aligned withthe receiver of the gun. The front sight 6 just described has theadvantage of making it possible to center the gun receiver and the gunbarrel to one another. This can be done, for example, by locking theposition of the gun, sighting in on a target at 100 yards, firing thegun several times, and measuring the distance the strike points are awayfrom the sighted target point. The front sight 6 is then adjusted tocompensate for this distance. When the gun is fired again at the target,it will be found that the sighted target point and the strike point willbetter coincide. This process may be repeated until the strike point andthe target point are acceptably close to one another. The result of thisprocess is that gun receiver and the gun barrel are aligned with oneanother, i.e., centered, and no further adjustments need be made to thefront sight 6. Thereafter, all windage and elevation adjustments tosight in on a target can be made solely with the windage and elevationcontrols of the rear sight.

Preferably, the front and rear sights of the present invention areprovided with markings and pointers to indicated their windagepositions. Examples of such markings and pointers are shown in FIGS. 3,17, and 21A. Front sight 6 has pointer line 154 located on the center ofthe shooter-facing side of the front base support 116 which interactswith hash lines 158 on front base plate 108. Rear sight 8 has pointer156, which is attached to rear base cradle 30 by the two screws 160,which interacts with scale marks 162 on rear aperture housing 36.Preferably, the markings are spaced so as to indicate the proper “minuteof angle” (this term is defined in the next paragraph) in order toassist the shooter set the windage of the front and rear sights 6, 8, 8a, 8 b, 8 c, 8 d.

Since movement from one detent-locked position to the next conveys tothe shooter an audible or tactile-sensible click, it is preferred thatthe detent-locked positions of at least one of the windage and elevationknobs 52, 78 of the rear sights 8, 8 a, 8 b, 8 c, 8 d and thedetent-locked position of the elevation knob 138 of the front sight 6 bespaced so that movement from one detent-locked position to the nextcorrelates to a known amount of target point displacement at a selectedtarget distance. In the art, a standard unit for target point elevationdisplacement is the “mil”. One mil is equivalent to a target pointelevation displacement of 1 meter at a target distance of 1,000 meters.Another standard unit for target point displacement in the art is a“minute of arc” or “minute of angle” or “MOA”. One MOA is approximatelyequal to 1 inch of target point displacement at a target distance of 100yards. Most preferably, the spacing between clicks for the rearelevation knob 78 of the rear sights 8, 8 a, 8 b, 8 c, 8 d is equivalentto one-sixth mil, and the spacing between clicks for the rear windageknob 52 is equivalent to one-quarter MOA.

It is to be understood that although many of the embodiments of thepresent invention are described as using detent mechanisms, front orrear sights having fewer or no detent mechanisms are also within thecontemplation of the present invention. With regard to those embodimentsof the present invention which utilize one or more detent mechanisms,any detent mechanism known to those skilled in the art may be employed,although those described in detail herein are preferred.

It is preferred that the components of the embodiments of the presentinvention be machined to have as small clearances between one another asis economically feasible for the application in which the iron sightingsystem is to be employed. Small clearances eliminate unwanted movementcommonly referred to as “slop” and thereby provide for a more rigid andreliable iron sighting system.

Preferably, at least one of the front and rear sights of the embodimentsof the present invention are provided with markings or indicatorsadjacent to their respective sighting points to aid the shooter inacquiring and lining up a target, i.e., in acquiring a sight picture.Referring to FIGS. 4 and 21A, front sight 6 and rear sight 8 are shownas being provided with tritium night sight inserts 166, 164,respectively. Other examples of such markings or indicators includepainted white or florescent circles, dots, or lines.

While only a few embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art that manychanges and modifications may be made thereunto without departing fromthe spirit and scope of the present invention as described in thefollowing claims. All patent applications and patents, both foreign anddomestic, and all other publications referenced herein are incorporatedherein in their entireties to the full extent permitted by law.

1. An iron sighting system for a gun comprising a front sight having asighting point and a rear sight having a sighting point, wherein atleast one of the front sight and the rear sight includes a multiple-leadthread elevation screw post for vertically adjusting the sighting pointof the front or rear sight of which it is a part.
 2. The iron sightingsystem of claim 1, wherein the multiple-lead elevation screw post has adual-lead thread.
 3. The iron sighting system of claim 1, wherein therear sight has a multiple-lead elevation screw post and an aperturewindow, wherein the elevation screw post is adjustably controllable toposition the sighting point of the rear sight to a selected locationwithin the aperture window.
 4. The iron sighting system of claim 3,wherein the rear sight has a sight tip operably connected to theelevation screw post.
 5. The iron sighting system of claim 4, whereinthe rear sight also comprises at least one vertically oriented armhaving a scale corresponding to target distances in at least oneselected from the group consisting of feet, yards, meters, kilometers,and mils, and the sighting tip has at least one horizontal arm adaptedto cooperate with the scale to indicate the target distance whichcorresponds to the vertical position of the sighting point of the rearsight.
 6. The iron sighting system of claim 5, wherein the verticallyoriented arm comprises a longitudinal slot having opposing walls, andthe distal end of the sighting tip horizontal arm is movably confined bythe slot walls.
 7. The iron sighting system of claim 5, wherein thevertical arm has a side face having a second scale corresponding totarget distances in at least one selected from the group consisting offeet, yards, meters, kilometers, and mils, the second scale beingadapted to cooperate with the sighting tip to indicate the targetdistance which corresponds to the vertical position of the sightingpoint of the rear sight.
 8. The iron sighting system of claim 3, furthercomprising a detent-lockable knob operably connected to the elevationscrew post such that rotation of the knob from one detent lockableposition to the next corresponds to a vertical movement of the sightingpoint of the rear sight about one-sixth mil.
 9. The iron sighting systemof claim 1, wherein at least one of the front sight and the rear sightfurther comprises a windage adjustment mechanism adapted to move thesighting point of the front or rear sight of which it is a parttransverse to the sighting direction of that front or rear sight. 10.The iron sighting system of claim 1, wherein the rear sight has awindage adjustment mechanism having a windage knob operably connected toa lateral screw post such that rotating the windage knob causes alateral movement of the sighting point of the rear sight.
 11. The ironsighting system of claim 10, wherein the windage knob is detent-lockableand is operably connected to the lateral screw post such that rotationof the windage knob from one detent lockable position to the nextcorresponds to a lateral movement of the sighting point of the rearsight about one quarter minute of angle.
 12. The iron sighting system ofclaim 10, wherein the windage adjustment mechanism is adapted to permitthe windage knob to be selectively located on the shooter's right orleft.
 13. The iron sighting system of claim 1, wherein at least one ofthe front sight and the rear sight comprises a tritium sight insertpositioned to indicate the location of the sighting point of the frontor rear sight of which the tritium sight insert is a part.
 14. The ironsighting system of claim 1, wherein the rear sight further comprises abase, an upper portion, and a plunger position stop, the upper portionbeing operably connected to the base to permit the upper portion torotate between a storage position and an operating position, the plungerposition stop being operably connected to the base and adapted toreleasably lock the upper portion in at least one of the storageposition and the operating position.
 15. The iron sighting system ofclaim 14, wherein the plunger position stop has a plunger having atleast one selected from the group consisting of a flat head and a V-slothead.
 16. The iron sighting system of claim 14, wherein the plungerposition stop comprises a plunger and a plurality of springs adapted tourge the plunger against the upper portion.
 17. The iron sighting systemof claim 14, wherein the base comprises a base plate and a cradle,wherein the cradle is adapted to rotatably carry the upper portion, thebase plate is adapted to be fastened to the gun, and the cradle isfastened to the base plate.
 18. The iron sighting system of claim 14,wherein the base comprises a cradle, wherein the cradle is adapted torotatably carry the upper portion and the cradle is adapted to befastened to the gun.
 19. The iron sighting system of claim 1, whereinthe front sight has a windage adjustment mechanism.
 20. The ironsighting system of claim 19, wherein the windage adjustment mechanismhas a selectively lockable dovetail joint, the dovetail joint beingadapted to selectively allow the sighting point of the front sight tolockably move transversely with respect to the sighting direction of thefront sight.
 21. The iron sighting system of claim 19, furthercomprising an upper portion having an aperture window, a detent lockablecontrol knob, and a control knob window, wherein the control knob isretained within the control knob window and is operably connected to theelevation screw post of the front sight so that selectively turning theelevation knob vertically adjusts the sighting point of the front sightwithin the aperture window.
 22. The iron sighting system of claim 21,wherein the elevation screw post of the front sight has a slot and theupper portion has a pin, the pin and slot cooperating to prevent theelevation screw post of the front sight from rotating about itslongitudinal axis.
 23. The iron sighting system of claim 19, wherein theelevation screw post of the front sight includes a tritium sight insertpositioned to indicate the location of the sighting point of the frontsight.
 24. The iron sighting system of claim 1, further comprising agun, wherein the front sight and the rear sight are operably connectedto the gun.
 25. The iron sighting system of claim 3, further comprisinga gun, wherein the front sight and the rear sight are operably connectedto the gun.
 26. The iron sighting system of claim 5, further comprisinga gun, wherein the front sight and the rear sight are operably connectedto the gun.
 27. The iron sighting system of claim 9, further comprisinga gun, wherein the front sight and the rear sight are operably connectedto the gun.
 28. The iron sighting system of claim 10, further comprisinga gun, wherein the front sight and the rear sight are operably connectedto the gun.
 29. The iron sighting system of claim 14, further comprisinga gun, wherein the front sight and the rear sight are operably connectedto the gun.
 30. The iron sighting system of claim 19, further comprisinga gun, wherein the front sight and the rear sight are operably connectedto the gun.
 31. A rear sight for a gun iron sighting system comprising asighting point and a multiple-lead thread elevation screw post forvertically adjusting the sighting point.
 32. The rear sight of claim 31,further comprising a sight tip operably connected to the elevation screwpost.
 33. The rear sight of claim 32, further comprising at least onevertically oriented arm having a scale corresponding to target distancesin at least one selected from the group consisting of feet, yards,meters, kilometers, and mils, and the sighting tip has at least onehorizontal arm adapted to cooperate with the scale to indicate thetarget distance which corresponds to the vertical position of thesighting point.
 34. The rear sight of claim 33, wherein the verticallyoriented arm comprises a longitudinal slot having opposing walls, andthe distal end of the sighting tip horizontal arm is movably confined bythe slot walls.
 35. The rear sight of claim 33, wherein the vertical armhas a side face having a second scale corresponding to target distancesin at least one selected from the group consisting of feet, yards,meters, kilometers, and mils, the second scale being adapted tocooperate with the sighting tip to indicate the target distance whichcorresponds to the vertical position of the sighting point.
 36. The rearsight of claim 31, further comprising a detent-lockable knob operablyconnected to the elevation screw post such that rotation of the knobfrom one detent lockable position to the next corresponds to a verticalmovement of the sighting point of about one-sixth mil.
 37. The rearsight of claim 31, further comprising a windage adjustment mechanismhaving a windage knob operably connected to a lateral screw post suchthat rotating the windage knob causes a lateral movement of the sightingpoint.
 38. The rear sight of claim 37, wherein the windage knob isdetent-lockable and is operably connected to the lateral screw post suchthat rotation of the windage knob from one detent lockable position tothe next corresponds to a lateral movement of the sighting point ofabout one quarter minute of angle.
 39. The rear sight of claim 37,wherein the windage adjustment mechanism is adapted to permit thewindage knob to be selectively located on the shooter's right or left.40. The rear sight of claim 31, further comprising a tritium sightinsert positioned to indicate the location of the sighting point. 41.The rear sight of claim 31, further comprising a base, an upper portion,and a plunger position stop, the upper portion being operably connectedto the base to permit the upper portion to rotate between a storageposition and an operating position, the plunger position stop beingoperably connected to the base and adapted to releasably lock the upperportion in at least one of the storage position and the operatingposition.
 42. The rear sight of claim 41, wherein the plunger positionstop has a plunger having at least one selected from the groupconsisting of a flat head and a V-slot head.
 43. The rear sight of claim41, wherein the plunger position stop comprises a plunger and aplurality of springs adapted to urge the plunger against the upperportion.
 44. The rear sight of claim 41, wherein the base comprises abase plate and a cradle, wherein the cradle is adapted to rotatablycarry the upper portion, the base plate is adapted to be fastened to thegun, and the cradle is fastened to the base plate.
 45. The rear sight ofclaim 41, wherein the base comprises a cradle, wherein the cradle isadapted to rotatably carry the upper portion and the cradle is adaptedto be fastened to the gun.
 46. A front sight for a gun iron sightingsystem comprising a sighting point and a multiple-lead thread elevationscrew post for vertically adjusting the sighting point.
 47. The frontsight of claim 46, further comprising a windage adjustment mechanism.48. The front sight of claim 47, wherein the windage adjustmentmechanism has a selectively lockable dovetail joint adapted toselectively allow the sighting point to be lockably moved transverse tothe sighting direction of the front sight.
 49. The front sight of claim46, further comprising an upper portion having an aperture window, adetent lockable control knob, and a control knob window, wherein thecontrol knob is retained within the control knob window and is operablyconnected to the elevation screw post so that selectively turning theelevation knob vertically adjusts the sighting point within the aperturewindow.
 50. The front sight of claim 49, wherein the elevation screwpost has a slot and the upper portion has a pin, the pin and slotcooperating to prevent the elevation screw post from rotating about itslongitudinal axis.
 51. The front sight of claim 46, wherein theelevation screw post includes a tritium sight insert positioned toindicate the location of the sighting point.